Cataracts & Cataract Surgery

Your eye works a lot like a camera. Light rays focus through your lens onto the retina, a layer of light-sensitive cells at the back of the eye. Similar to photographic film, the retina allows the image to be "seen" by the brain.


Eye like a camera:

Over time, the lens of our eye can become cloudy, preventing light rays from passing clearly through the lens. The loss of transparency may be so mild that vision is barely affected, or it can be so severe that no shapes or movements are seen--only light and dark. When the lens becomes cloudy enough to obstruct vision to any significant degree, it is called a cataract. Eyeglasses or contact lenses can usually correct slight refractive errors caused by early cataracts, but they cannot sharpen your vision if a severe cataract is present.

Mature Cataract:

The most common cause of a cataract is aging. Other causes include trauma, medications such as steroids, systemic diseases such as diabetes, and prolonged exposure to ultraviolet light. Occasionally, babies are born with a cataract.

Cataracts typically develop slowly and progressively, causing a gradual and painless decrease in vision. Other changes you might experience include blurry vision; glare, particularly at night; frequent changes in your eyeglass prescription; a decrease in color intensity; a yellowing of images; and in rare cases, double vision.
As the eye's natural lens gets harder, farsighted (presbyopic) people, who have difficulty focusing up close, can experience improved near vision and become less dependent on reading glasses. However, nearsighted (myopic) people become more nearsighted, causing a worsening in their distance vision. Some kinds of cataracts affect distance vision more than reading vision. Others affect reading vision more than distance vision.

Reducing your exposure to ultraviolet light by wearing a wide-brimmed hat and sunglasses may reduce your risk for developing a cataract. Once a cataract has developed, however, there is no cure except to have it surgically removed.

With a routine, outpatient surgical procedure, Dr. Haas can remove the cataract using a small incision that usually does not require any stitches.  A synthetic intraocular lens (IOL) is usually inserted at the time of cataract extraction to replace the focusing power of the natural lens. IOLs can be monovision (fixed-focus for a preset distance) or multifocal, which allows focused vision at many distances. The time to have cataract surgery is when the cataract is affecting your vision enough to interfere with your normal lifestyle.



IOL in place: 

Cataract surgery is a very successful operation. One and a half million people have this procedure every year in the United States, and 98+% have a successful result. As with any surgical procedure, complications can occur during or after surgery, and some are severe enough to limit vision. But in most cases, vision, as well as quality of life, improves.

Multifocal and Accommodative Intraocular Lenses to Treat Cataract

When you have a cataract, the lens of your eye becomes cloudy. Light cannot pass through the lens easily, and your vision becomes blurred. During cataract surgery, Dr. Haas removes the cloudy, natural lens and replaces it with a clear, artificial lens called an intraocular lens (IOL). The IOL helps your eye regain its focusing ability and allows you to see clearly again.

The most common type of IOL is the monofocal or fixed-focus IOL. The monofocal lens helps you attain clearer vision at one distance. Note that eyeglasses and contact lenses are still required in order for you to see clearly at all ranges of distance with this type of lens. 

Another type of IOL is the multifocal IOL. The multifocal lens has several rings of different powers built into the lens. The part of the ring you look through will determine if you can see clearly at far, near, or intermediate distances.  Multifocal lenses maximize the chance that a person can become completely spectacle independent after cataract surgery, but they still cannot assure this will happen for everyone.  There is also the chance that some loss of contrast sensitivity can occur due to the rings within the lens.  For this reason people with macular problems are not good candidates for multifocal lenses.

Multifocal IOL: 

Multifocal (close up):

A third type of IOL is the accommodative IOL. The accommodative lens has a hinge designed to work with your eye muscles, allowing the lens to move forward as the eye focuses on near objects and backward as the eye focuses on distant objects. This movement allows you to focus clearly at different distances, although glasses are still often needed for small print.  At this time, accommodative lenses alone will not let a person accommodate sufficiently for clear vision at all distances without the help of a small prescription.

Accommodating IOL:  

A fourth type of IOL is the toric IOL.  The toric IOL has astigmatism built-in and can improve mild to moderate degrees of astigmatism or cylinder in the eye.  This allows people with astigmatism to have better uncorrected vision after they undergo cataract surgery than they would with a traditional, monofocal IOL.


Implanting an IOL takes about 20 minutes and is an outpatient procedure. In addition to a preoperative eye exam, Dr. Haas will take measurements of your eyes and will give you topical or local anesthesia during the surgery. He makes small incisions close to the edge of the cornea and then inserts a small, ultrasound instrument to break up the center of the eye's natural lens (cataract). This cataract is then vacuumed out through one of the incisions. Dr. Haas then folds and inserts the new IOL through the same incision. These incisions are usually self-sealing and require no stitches, though stitches are sometimes placed if the wound doesn't completely self-seal. Once implanted, the new IOL allows you to see more clearly, though sometimes a new glasses prescription is required for your best possible vision.

Risks associated with implanting IOLs include overcorrection or under-correction, infection, increased floaters, retinal detachment, dislocation of the implant, retinal swelling, halos, glare, dry eye, decreased contrast sensitivity, clouding of a portion of the IOL, and loss of vision. Most symptoms are mild and will improve over time, and it is important to discuss your personal expected outcome with Dr. Haas before surgery, to make sure all of your questions are answered.
If you are going to have cataract surgery, we will discuss which IOL will be best for you and your particular vision needs.


Phacoemulsification (Phaco) is the most common surgical method used to remove a cataract.  It is the ultrasonic probe that is inserted into the eye to break up and vacuum out the cataract. The actual instrument has a much smaller width than a pencil or pen.


After phacoemulsification is complete, the new lens (IOL) is inserted into the eye through the same small incision.

IOL in eye after phaco:

Posterior Capsulotomy (Yag)

A posterior capsulotomy (Yag) is a laser procedure that is sometimes necessary after cataract surgery.  During cataract surgery, part of the front (anterior) capsule of the eye's natural lens is removed to gain access to and remove the lens. The clear, back (posterior) capsule remains intact and supports an intraocular lens (IOL), an acrylic or silicone disc that is implanted in the eye and replaces the natural lens. As long as that capsule stays clear, you will experience good vision. But in 10% to 30% or more of cases, the posterior capsule loses its clarity over several months to years. When this happens, Dr. Haas can create an opening in the capsule using a Yag laser in order to restore normal vision. This procedure is called a posterior capsulotomy.